Ultimate Facebook settings won't update. Hangs on "Checking API Settings"

We've been having issues with people unable to update their settings for the Ultimate Facebook plugin. It seems to be related to the fact that it hangs on "Checking API Settings". So far, it fails every time in the edge browser and internet explorer, and happens intermittently in chrome (though once it goes to "Successfully connected to NTM Blogs", then it doesn't fail anymore). I just updated to the most recent version of the plugin (2.8.1) and are on WordPress 4.2.5